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Herpes Simplex Keratitis. Branched dendritic lesion seen on the cornea in a patient with herpes simplex virus1. (Photo contributor: Lawrence B. Stack, MD.)


1The authors acknowledge the special contribution of Frank Birinyi, MD, Thomas F. Mauger, MD, Andrew Hendershot, MD, Marc E. Levsky, MD, and Paul DeFlorio, MD, for portions of this chapter written for the previous editions of this book.

Clinical Summary

The ocular conjunctiva can be a window to determining systemic disease. An unhealthy pale appearance of the palpebral conjunctiva is a sign of anemia. Anemia is defined as a reduced count of circulating red blood cells and can occur through blood loss or pathways that hinder red blood cell production. Patients with chronic blood loss may have long-standing anemia with compensatory mechanisms. Macrocytic anemias can result from any process that causes reticulocytosis, folate or vitamin B12 deficiencies, alcohol abuse, liver disease, or hypothyroidism. Microcytic anemia is commonly due to iron deficiency, disorders of heme synthesis, thalassemias, or chronic disease. In the emergency department (ED), clinical priorities for an anemic patient include determining hemodynamic stability, chronicity of the anemia, and the suspected underlying cause.

Management and Disposition

In the acute setting, one should rule out causes of acute blood loss and initiate resuscitation as indicated. Patients may require blood transfusion if symptomatic or if they have comorbid risk factors for poor outcome. A complete blood count with differential to delineate the type of anemia and examine for other cell line deficiencies should always be formed. Patient disposition is determined by the underlying cause of the anemia, symptoms associated with the anemia, and the patient’s hemodynamic stability.


  1. Conjunctival pallor is a simple physical exam finding that can identify anemic patients.

  2. The decision to transfuse red blood cells in an anemic patient is multifactorial. In hemodynamically stable patients without symptoms, most guidelines suggest a transfusion threshold between 7 and 8 g/dL with consideration of individual patient characteristics.

  3. An anemic patient with acute coronary syndrome requires transfusion, not aspirin.


Conjunctival Pallor. Conjunctival pallor is noted in this patient with anemia (A) that is improved after blood transfusion (B). (Photo contributor: Kevin J. Knoop, MD, MS.)

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